(i) Technical Field
A certain aspect of the embodiments discussed herein is related to a method for fabricating a semiconductor device.
(ii) Related Art
There is known a semiconductor device using silicon carbide (SiC). For example, nitride-based semiconductor layers (for example, a GaN-based semiconductor layer) are formed on a substrate to form a high electron mobility transistor (HEMT) capable of outputting high power. There is also known a semiconductor device in which a via hole is formed in the SiC substrate (see Japanese Patent Application Publication No. 2005-322811).
Conventionally, a via hole is formed in the SiC substrate by forming a via receiving pad on a semiconductor layer on the surface of the substrate and etching the substrate and the semiconductor layer from the back surface of the substrate continuously. However, the via receiving pad may be partly removed by etching. If etching is controlled to prevent the via receiving pad from being removed, the etching rate decreases.